The present invention relates to machines having a hydrostatic transmission such as a tractor, and more particularly, to a ground drive control assembly having a combined rocking foot pedal and shift assembly for effecting forward and reverse motion of the machine.
It is conventional to provide tractors and similar machines with hydrostatic transmissions for controlling the speed, direction, and pulling power of the tractor. Tractors of this type have also been provided with a rotatable control lever which operates in cooperation with a rocking foot pedal. The control lever is rotated in one direction for forward motion of the machine and is rotated in the opposite direction for reverse motion of the machine. The speed of the tractor in either direction is proportional to the amount the foot pedal is depressed. A ground drive control assembly of the type just described is illustrated in U.S. Pat. No. 4,040,306, assigned to the assignee of the present invention.
There is a disadvantage to the ground drive control assembly shown in the aforementioned patent. When the foot pedal is depressed for increasing speed, the rotatable control lever tends to move toward a neutral position which gives the operator the misconception that the control lever is not functioning properly. Thus, there has been a need for a drive control assembly which overcomes this disadvantage while providing improved operation as compared to prior constructions.